Soak the Fruit:
In a large bowl, soak the sultanas, currants, raisins, and mixed peel (if using) in brandy, rum, or fruit juice. Let the fruit soak for at least 4 hours or overnight for the best results.
Prepare the Cake Tin:
Preheat your oven to 150°C (300°F). Line a round cake tin with baking paper, ensuring the sides and bottom are well covered.
Mix the Wet Ingredients:
In a large mixing bowl, cream together the softened butter and brown sugar until light and fluffy. Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract and orange juice (if using).
Add the Dry Ingredients:
Sift the plain flour, baking powder, cinnamon, nutmeg, allspice, and salt into a separate bowl. Gradually fold the dry ingredients into the wet mixture until well combined.
Incorporate the Fruit and Nuts:
Gently fold in the soaked dried fruits, almonds, and mixed peel. Stir until evenly combined.
Bake the Cake:
Spoon the batter into the prepared cake tin and smooth the top. Bake for 1.5 to 2 hours, checking for doneness by inserting a skewer into the center of the cake. If it comes out clean, the cake is ready. If the top starts to brown too quickly, cover it loosely with aluminum foil and continue baking.
Cool and Store:
Allow the cake to cool in the tin for about 10 minutes before transferring it to a wire rack to cool completely. Once cooled, wrap the cake tightly in plastic wrap and then foil. Store it in an airtight container in a cool, dry place. For the best flavor, let the cake rest for at least a week before serving.